Non-woven fibrous material bonded with ethylene/vinyl chloride interpolymers

ABSTRACT

Nonwoven fibrous products bonded with ethylene/vinyl chloride/acrylamine/N-(alkoxymethyl)acrylamide interpolymers.

United States Patent Andersen Nov. 25, 1975 [54] NON-WOVEN FIBROUSMATERIAL 3,503,918 3 1970 LeSota 260/29.6 TA

BONDED WITH ETHYLENE/VINYL 3,629,209 12/1971 McDonald et a1. 260/80.73

3,632,424 1/1972 Graham et a1. 117 155 UA CHLORIDE INTERPOLYMERS3,647,615 3/1972 Fallwell 161/170 [75] Inventor: Harry M. Andersen,Ballwin, M0. 3,658, 4/l972 Otfinger 260/29.6 TA

3,700,492 10/1972 Bergomi 260/29.6 TA

[ Asslgneel Monsanto Company, LOUIS, 3,755,233 8 1973 Fallwell 260/80.73

- 3,758,429 9 1973 Fallwell 260/80.73

[22] 1973 3,803,072 4 1974 Graham et a1. 117 155 UA 211 Appl. No.:328,165

Related US. Application Data Continuation-impart of Ser. No. 255,367,May 22, 1972, abandoned.

References Cited UNITED STATES PATENTS 2/1969 Deex 260/80.73

Primary ExaminerGeorge F. Lesmes Assistant ExaminerWi11iam R. Dixon, Jr.

Attorney, Agent, or Firm-N. E. Willis; H. B. Roberts; F. D. Shearin [57]ABSTRACT Nonwoven fibrous products bonded with ethylene/vinylchloride/acrylamine/N-(alkoxymethyl)acrylamide interpolymers.

11 Claims, No Drawings NON-WOVEN FIBROUS MATERIAL BONDED WITI-IETI-IYLENE/VINYL CHLORIDE INTERPOLYMERS RELATED CASES This applicationis a continuation-in-part of application Ser. No. 255,367, filed May 22,1972 now abandoned.

BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION This inventionrelates to nonwoven fibers bonded with acrylamide/ethylene/vinylchloride/N-(alkoxymethyl)-acrylamide interpolymers.

2. DESCRIPTION OF THE PRIOR ART Many known polymers are useful asbinders for nonwovens in their latex or solution form. Generally,latices are used for ease of application. However, many of these laticesare unsatisfactory for a variety of reasons. Some require externalcross-linking agents. Others lack mechanical or shear strength,especially at high temperatures. Still others require long curing timesat high temperatures.

Other latices do not provide nonwoven fabrics having satisfactoryresistance to solvents, laundering or dry cleaning. Somer adverselyaffect the strength, hand or drape of the bonded fibers.

Nonwovens bonded with interpolymers that do not possess any of the abovementioned disadvantages would be an advancement in the art.

BRIEF DESCRIPTION OF THE INVENTION In accordance with this invention, itwas surprisingly found that nonwovens bonded with ethylene/vinylchloride/acrylamide/N-(alkoxymethyDacrylamide interpolymers havesatisfactory resistance to solvents, laundering and dry cleaning as wellas adequate strength, hand and drape. Novel latices are selfcrosslinkable and have high shear or mechanical stability. They requireshort curing times at low temperatures. These interpolymers comprise:

A. ethylene; (E)

B. vinyl chloride; (VCL) 'C. acrylamide or acrylamide in combinationwith another polar monomer selected from the group consisting ofmethacrylamide; N-(alkyl)acrylamide; N-(alkyl)meth-acrylamideunsaturated carboxylic acids; alkali metal salts and ammonium salts ofunsaturated carboxylic acids; acrylylamides and methacrylylamides ofaminoalkanoic acids; and alkyl and hydroxy alkyl esters of unsaturatedcarboxylic acids; and

D. a compound represented by the formula wherein X represents CH orhydrogen and Y represents an alkyl group containing 1 to carbon atoms.

DETAILED DESCRIPTION OF THE INVENTION The term nonwoven fibrousmaterial" as used herein means a consolidated mass of fibers laid downinclude N-(alkyl)acrylamides and N-(alkyl)methacrylamides containing 1to 8 carbon atoms in the alkyl group; unsaturated carboxylic acidsespecially the dicarboxylic acids having a backbone containing 2 to 6carbon atoms; acrylylamides and methacrylylamides of amino alkanoicacids containing 2 to 6 carbon atoms; and alkyl and hydroxy alkyl estersof polycarboxylic acids containing 1 to 4 carbon atoms in the alkylgroup, especially such esters of dicarboxylic acids having a backbonecontaining 2 to 6 carbon atoms.

Specific examples of polar monomers which may be used includeN-methylacrylamide; N-ethylacrylamide; N-propylacrylamide;N-methylmethacrylamide; N- ethylmethacrylamide; N-propylmethacrylamide;maleic, fumaric, itaconic, aconitic, and citraconic acids and alkalimetal and ammonium salts of such acids preferably the sodium, potassiumor ammonium salts; monoethyl maleate; dipropyl fumarate; 2-hydroxyethyland 2-hydroxypropyl esters of maleic, fumaric, itaconic, aconitic, andcitraconic acids.

Examples of compounds represented by Formula I include:

FORMULA NAME N( methoxymethyhacrylamide (NMA) N(methoxymethyl)methacrylamide (NMMA) BMA and BMMA are preferred.

The interpolymers of this invention generally contain about to 70%ethylene, 30 to 95% vinyl chloride, 0.1 to of acrylamide or acombination of acrylamide with another polar monomer and 0.1 to 10% of acompound represented by Formula I. Preferably, the copolymer comprises20 to 40% ethylene, 60 to 85% vinyl chloride, 2 to 6% acrylamide oracrylamide in combination with another polar monomer and 2 to 6% of acompound represented by Formula I. All percentages are by weight, basedon the total weight of the interpolymer. When a combination ofacrylamide and another polar monomer is used in the practice of thisinvention, generally at least 10% by weight of such combination isacrylamide, preferably 50% and more preferably 80%.

The interpolymers are used in the form of a latex or as an organicsolution after coagulation with alcohol such asmethyl alcohol and ethylalcohol. The.interpolymers are soluble in organic solvents such asdimethyl formamide, tetrahydrofuran and dimethylacetamide. I

Latices of this invention are the preferred form. They have highmechanical strength or stability. That is, they .resist high shearforces and do not break when subjected to a shear rate of from about 10to 10 seconds. 1 They are highly cross-linked, i.e., at least 60 to 95%and preferably at least 80% by weight insoluble in a suitable solvent.No external cross-linking agents are needed and curing conditions aremild. For example, curing takes place at a temperature of from about 100to 180C in from 3 to 25 minutes. They maintain their strength when usedat higher temperatures.

lnterpolymer latices of the present invention generally contain fromabout 5 to about 65% of the interpolymer by weight, preferably suchlatices contain from about 10 to about 60% by weight of interpolymer forease of application by means of dripping, soaking, spraying and'thelike. The balance is generally water which may also contain minoramounts of reactants or by-products. They have an average particle sizeof about 500 angstroms to about 2,000 angstroms and a number averagemolecular weight from about 7,000 to about 35,000 as measured by gelpermeation chromotography or intrinsic viscosity.

These new interpolymers, surprisingly, are particularly amenable tohydrolytic modification by the use of small quantities of a stronglyalkaline material such as alkali metal hydroxide, or quaternary ammoniumhydroxide, such as tetramethyl ammonium hydroxide, or by a strong acidsuch as the mineral acids, e.g., hydrochloric, sulfuric, phosphoric andnitric. The base or acid used preferably has an ionization constanthigher than 10 at 25C. They are generally treated with acid or base inan amount which is chemically equivalent to up to about 100 percent ofthe amide equivalent in the interpolymer. An amount of from about 10% toabout 90% is preferred with an amount of from about 50% to 80% beingmore preferred.

The interpolymers of this invention can be prepared by various meanswell known in the art. Preferably, they are prepared by emulsionpolymerization. For example, they are prepared by first mixing ethyleneand vinyl chloride in an aqueous medium in the presence of any suitableanionic or nonionic emulsifier and any initiator capable of generatingfree radicals in the chemical mixture at the chosen reaction temperatureand pressure. Acrylamide and a compound represented-by Formula I inaqueous solution is added to the polymer- 4 izing ethylene and vinylchloride mixture gradually throughout the reaction. This addition ispreferably begun soon after polymerization starts and is added linearlywith conversion of monomer to polymer.

The interpolymers of this invention are more preferably prepared byprocesses which comprise mixing ethylene and vinyl chloride monomers inthe presence of an alkaline or acidic buffered reduction-oxidation(redox) initiator-catalyst system water and from about 1% to about 8%based upon the polymer product of an anionic emulsifying agent andreacting the mixture at a temperature, pressure and for a sufficienttime to cause polymerization between the ethylene and vinyl chloride tobegin. Then, acrylamide and one of the compound represented by Formula Iin an appropriate diluent such as water is introduced into the reactionmixture.

The process is described in more detail in US. Pat. No.

3,428,582 andthe subject matter thereof is expressly incorporated hereinby reference.

Surprisingly, it was found that when the interpolymers of the presentinvention were prepared by emulsion polymerization that unless theacrylamide or another polar monomer is present, the latex coagulated onventing.

The bonded nonwoven fibrous products of this invention can be formed ofeither natural or synthetic fibers or any combination thereof with theselection of the fiber merely depending upon the specific end useintended for the bonded nonwoven fibrous product. Among the fibers thatcan be used in accordance with this invention are natural fibers, forexample, wood, jute, sisal hemp, cotton, cotton Iinters, silk, mohair,cashmere, asbestos, wool and glass, and synthetic fibers, for example,rayon cellulose esters such as cellulose acetate, polyvinyl chloride,polyvinyl acetate, polyacrylanitrile and copolymers thereof, polyethylvene, polypropylene and the like, polyesters such as ethyleneglycolterephthalate polymers, and polyamides of the nylon type.

In many applications, the bonded nonwoven fibrous products of thisinvention are prepared'from a plurality of natural fibers, or aplurality of synthetic fibers, or a combination of natural and syntheticfibers. Combinations of wood fiber and cotton fiber can beadvantageously employed in end products such as shoe liners and thelike. In general, the wood fiber comprises the major amount of the fibercontent ofsuch bonded nonwoven fibrous products. Combinations of glassfibers and asbestos fiber are generally employed in insulatingapplications. The weight ratio of glass fiber to cellulosic fiber insuch bonded nonwoven fibrous products is usually from 1:10 to about10:1.

In wearing apparel applications, a combination of wood fibers and nylonfibers or a combination of wood fibers and rayon fibers can beadvantageously employed. Combinations of wood fiber and nylon fiber aswell as combinations of wood fiber and polyester fiber are also widelyemployed in various applications where reinforced sheeting is required.In such combinations of natural and synthetic fibers, the weight ratioof natural fiber to synthetic fiber is generally from about 1:20 toabout 20:1 and preferably from about 1:1- to about 3:1.

The nonwoven fibrous materials useful in the preparation of the bondednonwoven fibrous products of this invention can be prepared by anymethod known to the art. Thus, the nonwoven fibrous material can be madeof fibers deposited in a random manner as well as fiber oriented oraligned along a particular axis. Nonwoven fibrous materials in the formof two-dimensional webs can be prepared by the following methods.Oriented webs are produced using conventional web-style machines, suchas openers, pickers, cards, or garnetts. Cross-laid webs are made in amanner similar to oriented webs, except that the fibers are carefullyplaced at right angles to the machine direction to improve cross-wisestrength.

Random webs are produced in air-lay machines, and the nonwoven fibrousmaterial has equal strength in all directions. In the air-lay method,continuous filaments are fed through a cutter or breaker whichdischarges the fibers into the discharge side of a, blower. Suitableconduits are provided to guide the fibers to a collecting screen orair-pervious structure for collecting the fibers in the form desired.The screen may bein the form of an endless traveling belt passingthrough the lower portion of a tower into' the upper portion of whichthe blown fibers are introduced by the conduit. A suction box may beplaced beneath the traveling screen to assist in the deposition of thefibers thereon. Instead of using a traveling flat screen, a stationaryformed screen may be used. For example, the screen may take the form ofa hat shaped cone, such as thatused in the felt hat-making industry.Alternatively, it may have any other form which is suitable to producethe desired shape of the bonded nonwoven fibrous product such as arectangular tray. As is the case with the endless traveling belt,suction may also be applied beneath the stationary screen to assistdeposition of the fibers thereon.

Random webs are also produced by the direct spray method from a solutionof molten mass of the fiber materials. This is the conventionalprocedure for the formation of glass fibers or mineral wool fibers, aswell as those of nylon or thermoplastic materials, adapted to bedissolved in a suitable solvent or to be melted. The solution or melt isdirected to nozzles or jet-forming orifices and a high pressure fluidstream, such air, nitrogen or steam, is directed against the stream orstreams of filament-forming material to disrupt them and coagulate themas fibers in the vicinity of the orifices.- Electrostatic spinningmethods can also be employed for this purpose. As in the case of the useof blowers, the disrupted and dispersed fibers can be directed to thetop of the settling tower and allowed to settle with the aid of suctiondevices upon a suitable traveling or stationary screen at the bottom ofthe tower. This proce dure is particularly adapted to the production offibers of siliceous materials such as glass or mineral wool, as

' well as to thermoplastic resin fibers.

Wet random webs are formed from a slurry of dis persed fiber onpapermaking or modified papermaking machines. Spunbonded webs are madeof randomly oriented continuous filament fibers bonded at the crossoverpoint. The method includes extrusion of the continuous filament fibers,drawing to orient the fiber, some fiber entanglement by liquids or air,and bonding at the cross-over points.

The bonded nonwoven fibrous products of this invention are generallyprepared by a method which comprises consolidating the loose fibers intononwoven fibrous material having the strctural configuration of thedesired bonded nonwoven fibrous product, dispersing an interopolymerbonding agent of this invention within the nonwoven fibrous material,and heating the impregnated nonwoven fibrous material to a temperaturesufficient to coalescense and fuse the interpolyto cross-link theinterpolymer if a sulfur cross-linking agent is employed.

Another method for the preparation of the bonded nonwoven fibrousproducts of this invention which is particularly useful when thenonwoven fibrous material is formed by the air-lay method in an air-laymachine comprises contacting the fibers with an interpolymer dispersionor powder as they fall through the settling chamber to their point ofdeposition. This is advantageously carried out by spraying theinterpolymer dispersion or powder into the settling chamber at someintermediate point between the top and the bottom thereof. By sprayingthe fibers as they descend to the point of collection, it is possible toeffect a thorough distribution of the interpolymer bonding agent amongthe fibers before they are collected into the nonwoven fibrous material.In the production of certain fibrous products wherein a hot molten massof a polymer such as nylon or a fused siliceous mass or glass isdisrupted by jets of heated air or steam, the bonding agent dispersionor powder can be sprayed directly on the fibers while still hot so thatimmediately after deposition the bonding agent is set and it bonds andinterlocks the fibers in proper relationship. Still another methodinvolves adding the interpolymer to the fibers prior to consolidationas, for example, by adding the interpolymer to the aqueous fiber slurryin a modified papermaking process.

The interpolymer bonding agents of this invention can be applied to thefibers of the nonwoven fibrous material by any means known in the art.The interpolymer bonding agents are usually applied to the fibers of thenonwoven fibrousmaterial by application to the surface thereof, or bysubmersion of the nonwoven fibrous material in a liquid, thickened orfoamed dispersion so that the bonding agent penetrates into the interiorof the nonwoven fibrous material. Where the nonwoven fbirous material isa two-dimensional fabric in the form of a fleece or web, the bondingagents are usually applied in the form of an aqueous dispersion. In atypical application, the fabric is impregnated with the bonding agent bydipping or immersing the fabric in the dispersion to provide sufficientwet pickup of the bonding agent. The wetted, nonwoven fibrous materialin the form of a fleece or web can be passed between a pair of pressurerolls to effect substantially uniform impregnation and also to controlthe amount of the bonding agent applied. The impregnated nonwovenfibrous material is dried by conventional means known to the art inorder to remove all or a portion of the water and to effect coalescenceand fusion of the interpolymer within the nonwoven fibrous material. Thedrying temperature and drying time are dependent upon the size, shapeand cross-section of the impregnated, nonwoven fibrous material. Ingeneral,the drying temperature is controlled so that no appreciabledeterioration or degradation of the fibers or the interpolymer occurs.

The amount of bonding agent based on the weight of the fiber componentof the bonded nonwoven fibrous product can vary widely depending uponthe characteristics desired in the final product and the specific enduse. The bonded nonwoven fibrous products of this invention generallycontain from about 2% to about 200% of interpolymer based on the weightof the fibers. For the production of preforms intended to be convertedinto shaped articles, it is preferred to employ from about 2% to about10% of the bonding agent 7 based on the weight of the fibers. In theproduction of insulation materials, the amount of bonding agent employedgenerally falls in the lower part of the above range if the bondingagent is applied primarily adjacent to the surface or surfaces of theproduct or if it is applied in conjunction with other binders.

When the bonding agent is to serve mainly to bond the fibers together toform a bonded nonwoven fibrous product in which the maximum porosity isretained in conjunction with a minimum change of fiber hand and drapecharacteristics as well as an increase in tensile strength, there ispreferably employed from about 10 to about 70% by weight of bondingagent solids based on fiber content. The lower portion of this rangegenerally gives the maximum porosity and provides a minimum change inthe fiber hand and drape characteristics although in the higher portionof this range porosity is mainly retained and the fiber hand and drapecharacteristics are still evident. The bonded nonwoven fibrous productsthus obtained are advantageously used for many sanitary purposes, suchas table napkins, bibs, tablecloths, sanitary napkin covers, disposablediapers, disposable sheets, and surgical dressings and compresses. Whenthis amount of bonding agent is used there is relatively little or nowindow paning, i.e. the interstices between the fibers are left openleaving a highly porous bulky product. If desired, the density of theproduct can be modified by the application of various amounts ofpressure prior to, or in many cases, after the saturated nonwovenfibrous material has been heated for bonding.

Bonded nonwoven fibrous products containing from about 40 to about 150%by weight of bonding agent based on the weight of the fiber generallyfind use in the garment industry to provide interlining fabrics forcoats, dresses, collars, cuffs and the like and to provide outer wearingapparel fabrics, such as blouses, skirts, shirts, dresses and the like.Bonded nonwoven fibrous products containing the bonding agent in thisrange are also useful as curtain and drapery materials. In addition tothe general household and apparel uses mentioned above, the bondednonwoven fibrous products of this invention in which 10 to lO0% byweight of bonding agent based on the weight of the fiber is employedfind many light industrial uses as wiping cloths, filters and liningmaterials for packaging.

Bonded nonwoven fibrous products of the present invention which containfrom about 100 to about 200% by weight of the bonding agent based on theweight of the fiber are particularly useful for heavy industrial useswhere durability and resistance to wear are desired. Such uses includeindustrial gaskets, packings, filters and the like.

If desired, the aqueous interpolymer dispersion can also contain awetting agent to assist penetration of the nonwoven fibrous material towhich it is applied. The aqueous dispersions can also contain a foamingagent or they can contain a defoamer when the ingredients of the aqueousdispersion have a tendency to give rise to foaming and when such foamingis undesirable. The convention wetting agents such as the sodium salt ofdioctylsuccinic acid can be used and the conventional foaming anddefoaming agents can be employed such as sodium soaps including sodiumoleate for foaming and octyl alcohol or certain silicone antifoamingagents for defoaming.

The bonded nonwoven fibrous products of this invention are characterizedby high tensile strength, good 8 elongation, softness, good hand andflexibility, good drape and resistance to many common solvents anddetergents. With these properties, the bonded nonwoven fibrous productsof this invention are suitable for use in a wide variety of endapplications, many of which have been noted above and including, forexample, paperboard, cleansing tissues, toweling, wrappings for foodproducts, tea bags, wallpaper, mats, napkins, table cloths, heat orsound insulating materials, electrolytic condensers, luggage skin andinteriors, glue coated tape stocks, pressure sensitive tape stocks,masking sheets, pennants, banners, labels, book cover stocks, projectionscreens, gaskets, printing press top cover sheets, waterproof wrappingpaper, sandpaper backs, printing tape, hospital items such as caps,masks,

gowns, jackets, scrub pants, capes, shoe covers, wash cloths, pillowcases, wipes, bandages, alcohol preps, surgical dressings, napkins,cubicle curtains, drapes, diapers and sheets, filters for foodprocessing, motors, machines, air systems or liquid systems, electricalinsulators, tapes, ribbons, automobile head and arm rests, upholstery,stuffed pillows, fiberfills, sleeping bags, slip covers, bed spreads,blankets, curtains, window shades, carpeting (nonwoven), wearingapparel, clothing insulation, underwear, diapers, interfacing andinterliners (collars and cuffs). v

The bonding agents of this invention have been described as the solebonding agent for the bonded nonwoven fibrous products of thisinvention. However, for some applications, the interpolymers can beemployed in combination with termosetting, precondensate resins, such asaminoplasts, which are capable of cooperating with the bonding agent togive enhanced properties of launderability and dry cleaning resistanceto the bonded nonwoven fibrous products, particularly when they are inthe form of fabric material. The preferred aminoplast resins forblending with the interpolymers are the condensation products orprecondensates of urea and formaldehyde and ethylene, urea andformaldehyde.

The following examples will illustrate the invention. Parts andpercentages are by weight unless otherwise indicated.

EXAMPLE I This example illustrates the preparation of a 27/66.5/3.4/3.lweight percent E/VCL/acrylamide (ACRD)/BMA interpolymer latex.

Reaction Vessel Initial Charge -continued Reaction Vessel Initial ChargeBMA 51 gm (186 ml total) Polymerization 330 min/40ll920 psi ProductLatex 3530 gm pH 2.9 Polymer 1618 gm Surface Tension 46 dy/cm Ethylene27.4%

Viscosity l 12 cp VCL 66.5%

Tot. Sol. 47.2% ACRD 3.4%

Tg -7C BMA 3.1% SLS 1.7%

Initial Charge is added to a one gallon stirred autoclave then InitialMonomer is added. Polymerization is started by pumping in SE8 solution.Pressure is maintained by adding VCL on demand (758 g is used). Within aminute or two after polymerixation starts, the auxilary SLS stream isstarted, followed by the Mixed Stream and BMA at a rate proportional tothe VCL pumping rate. After 330 minutes, the reaction is stopped and thelatex rapidly vented through a ball valve at the bottom of the clave.

The latex did not break when subjected to a 10 seconds' rate of shear.

Cross-linking is determined as follows. A sample of Example 1 latex iscast on a glass plate, air-dried, and heat-treated in a circulating airoven for minutes at 150C. It is then weighed and soaked in a solvent,96% tetrahydrofuran/4% water, until extraction is complete (at leastfour hours). The specimen is then removed, blotted, dried and weighed.It is 71% insoluble. The higher the percent, the better thecross-linking.

EXAMPLE II An aqueous dispersion of 27.4/66.5/3.4/3.1 weight percentE/VCL/ACRD/BMAV interpolymer prepared substantially in accordance withExample I and containing about 48.5 weight percent polymer solids iscoagulated by means of isopropanol. The interpolymer is washed withwater and dried.

EXAMPLE III Interpolymers of the following composition are prepared andtested substantially in accordance with the procedure of Example Iabove.

AVG INSOL Particle In Composition Size Mw Tg, "C THF% E/VCL/ACRD/BMA27.0/66.5/3.4l3.l 690 64,000 --7.0 71 25.9/67.9/3.3l2.9 710 95,000 0.577

EXAMPLE IV Interpolymers of the following compositions are preparedsubstantially in accordance with the procedure of Example I above.E/VCL/ACRD/MMA E/VCL/ACRD-N-methylacrylamide/EMAE/VOL/ACRD-N-methylmethylacrylamide/AMA 10 E/VCL/ACRD-maleic acid/NMAElvCL/ACRD-2-hydroxyethyl fumaric acid/MMA E/VCL/ACRD-aconitic acid/BMMAEXAMPLE V Latices of Example IV are coagulated by means of isopropanoland are washed and dried.

EXAMPLE VI Preweighed samples of Hollingsworth and Vose nonwoven fabriccomposite comprising weight percent cellulosic fiber and 25 weightpercent nylon fiber are immersed in aqueous dispersions of E/VCL/ACRDl-BMA bonding agents. The aqueous dispersions contain 13.5 weight percentinterpolymer solids. The impregnated fabrics are passed through a sizepress, weighed, dried for about two minutes at a temperature of about118C and weighed. The bonded non-woven fabrics are subjected tocalendering through a single nip for smoothness and tested for hand anddrape characteristics, toughness and tensile strength. Hand and drapecharacteristics are determined qualitatively by touch and results aregiven on a scale of 1 through 10. Number 1 means very soft and highlyflexible. Number 10 means very rough and non-flexible. Tensile strengthis determined by TAPPI T404 08-61 with a table model Instron. Toughnessis determined by measuring the area under the stress strain curve.Results and further details are given in the Table below where theamount of bonding agent in the bonded nonwoven fabric is given inpercent by dry weight based on the weight of the fiber in the nonwovenfabric, tensile strength is given in lb./in., and toughness is given ininch-pounds.

EXAMPLE VII Following the procedure of Example VI, bonded fibers may beprepared by substituting for the bonding agent used in Example 111,those of Example IV What is claimed is:

l. A bonded nonwoven fibrous product comprising nonwoven fibrousmaterial bonded with an interpolymer consisting essentially of A. 5 to70% by weight based on the total weight of the interpolymer of ethylene;

B. 30 to by weight based on the total weight of the interpolymer ofvinyl chloride;

C. 2 to 10% by weight based on the weight of the interpolymer ofacrylamide or acrylamide in combination with a polar monomer selectedfrom the group consisting of methacrylamide; N-(alkyl) acrylamide;N-(alkyl) methacrylamide; unsaturated carboxylic acids; alkali metalsalts and ammonium salts of unsaturated carboxylic acids; acrylylamidesand methacrylylamides of aminoalkanoic acids; and alkyl and hydroxyalkyl esters of unsaturated 1 1 carboxylic acids and D. 2 to by weightbased on the total weight of the interpolymer of a compound representedby the formula 4. A product according to claim 3 wherein the nonwovenfibrous material is made of ha'tural fiber.

5. A product according to claim 4 wherein the natu ral fiber iscellulosic.

6. A product of claim 3 wherein the nonwoven fiber material is made ofsynthetic fiber.

7. A product according to claim 6 wherein the fiber is polyester fiberor polyamide fiber.

8. A product of claim 3 wherein the nonwoven fibrous material is acombination of natural fiber and synthetic fiber.

9. A product according to claim 3 wherein the interpolymer is present inan amount from about 2 weight percent to about 200 weight percent basedon the weight of the fiber.

10. A product according to claim 9 wherein X is H and Y is an alkylgroup containing 4 carbon atoms.

11. A product according to claim 2 wherein said interpolymer before usewas hydrolyzed by treating said amide moieties with an acid as a basehaving an ionization constant higher than about 10.

1. A BONDED NONWOVEN FIBROUS PRODUCT COMPRISING NONWOVEN FIBROUSMATERIAL BONDED WITH AN INTERPOLYMER CONSISTING ESSENTIALLY OF A. 5 TO70% BY WEIGHT BASED ON THE TOTAL WEIGHT OF THE INTERPOLYMER OF ETHYLENE;B. 30 TO 95% BY WEIGHT BASED ON THE TOTAL WEIGHT OF THE INTERPOLYMER OFVINYL CHLORIDE; C. 2 TO 10% BY WEIGHT BASED ON THE WEIGHT OF THEINTERPOLYMER OF ACRYLAMIDE OR ACRYLAMIDE IN COMBINATION WITH A POLARMONOMER SELECTED FROM THE GROUP CONSISTING OF METHACRYLAMIDE; N-(ALKYL)ACRYLAMIDE; N-(ALKYL) METHACRYLAMIDE; UNSATURATED CARBOXYLIC ACIDS;ALKALI METAL SALTS AND AMMONIUM SALTS OF UNSATURATED CARBOXYLIC ACIDS;ACRYLYLAMIDES AND METHACRYLYLAMIDES OF AMINOALKANOIC ACIDS; AND ALKYLAND HYDROXY ALKYL ESTERS OF UNSATURATED CARBOXYLIC ACIDS AND D. 2 TO 10%BY WEIGHT BASED ON THE TOTAL WEIGHT OF THE INTERPOLYMER OF A COMPOUNDREPRESENTED BY THE FORMULA
 2. A product according to claim 1 wherein (C)is acrylamide.
 3. A product of claim 2 wherein the interpolymer contains20 to about 40 weight percent of (A), 60 to about 85 weight percent of(B), 2 to about 6 weight percent of (C), and 2 to about 6 weight percentof (D).
 4. A product according to claim 3 wherein the nonwoven fibrousmaterial is made of natural fiber.
 5. A product according to claim 4wherein the natural fiber is cellulosic.
 6. A product of claim 3 whereinthe nonwoven fiber material is made of synthetic fiber.
 7. A productaccording to claim 6 wherein the fiber is polyester fiber or polyamidefiber.
 8. A product of claim 3 wherein the nonwoven fibrous material isa combination of natural fiber and synthetic fiber.
 9. A productaccording to claim 3 wherein the interpolymer is present in an amountfrom about 2 weight percent to about 200 weight percent based on theweight of the fiber.
 10. A product according to claim 9 wherein X is Hand Y is an alkyl group containing 4 carbon atoms.
 11. A productaccording to claim 2 wherein said interpolymer before use was hydrolyzedby treating said amide moieties with an acid as a base having anionization constant higher than about 10 4.